Osteotomy system and method of use

ABSTRACT

Disclosed is a bone cutting and shortening system and the method of using the same, the system comprising a bone plate and a cutting guide adapted to slidingly engage by inserting the cutting guide into the bone plate from the overhead direction, the cutting guide adapted to facilitate parallel cutting planes on a bone at precisely ascertainable offset distances, and the bone plate adapted to stabilize the shortened bone after cutting.

CLAIM OF PRIORITY

This application is being filed as a non-provisional patent applicationunder 35 U.S.C. § 111(a) and 37 CFR § 1.53(b). This application claimspriority under 35 U.S.C. § 119(e) to U.S. provisional patent applicationSer. No. 62/927,325 filed on Oct. 29, 2019, the contents of which areincorporated herein by reference

FIELD OF INVENTION

The invention relates generally to orthopedic implants and surgicaldevices and systems, and, in particular, to a plate and cutting guidesystem for use in bone osteotomy surgery and to stabilize a shortenedbone, including but not limited to, the ulnar bone.

BACKGROUND OF THE INVENTION

To treat certain orthopedic conditions and injuries, it is sometimesnecessary to shorten a bone. Most commonly this is accomplished byperforming an osteotomy, in which a portion of the bone is cut andremoved, the ends of the bone are joined and stabilized, and the bone isheld in compression to promote fusion of the ends, resulting in anoverall reduction of the bone's length. Described herein is a systemcomprising a bone plate and a cutting guide which facilitate performanceof an osteotomy and stabilization of the shortened bone.

SUMMARY OF THE INVENTION

It is an object of the instant invention to provide a bone cuttingsystem comprising a bone plate and a cutting guide adapted to slidinglyengage by inserting the cutting guide into the bone plate from theoverhead direction, the cutting guide adapted to facilitate parallelcutting planes on a bone at readily ascertainable offset distances.

The bone plate comprises a substantially rigid plate including anelongated body having a proximal end and a distal end and defining alongitudinal body axis; the plate comprising a bone contacting side, andopposing side, a left sidewall and a right sidewall, all of which extendbetween the proximal end of the plate and the distal end of the plateand all of which are substantially aligned with the longitudinal bodyaxis; a proximal elongated slot extending through the plate between theopposing side and the bone contacting side located adjacent to theproximal end of the plate, the proximal elongated slot adapted toreceive a bone screw; a distal elongated slot extending through theplate between the opposing side and the bone contacting side andadjacent to the proximal elongated slot but located distally on theplate relative to the proximal elongated slot, the distal elongated slotadapted to receive a bone screw; one or more bone screw holes extendingthrough the plate between the opposing side and the bone contacting sideand located distally on the plate relative to the distal elongated slot,the one or more screw holes adapted to receive a bone screw; a recess onthe opposing side of the plate; a left track recessed into the leftsidewall, the left track extending longitudinally between a track limitpoint and the proximal end of the plate, the left track being bound byan upper bounding wall, and a lower bounding wall, the lower boundingwall extending for the entire length of the left track while the upperbounding wall extends partially from the distal end of the left track toa location distal to the proximal end of the left track; and a righttrack recessed into the right sidewall, the right track extendinglongitudinally between a track limit point and the proximal end of theplate, the right track being bound buy an upper bounding wall, and alower bounding wall, the lower bounding wall extending for the entirelength of the right track while the upper bounding wall extendspartially from the distal end of the right track to a location distal tothe proximal end of the right track; wherein the portions of the lefttrack and the right track that are bound only by a lower bounding wallprovide an overhead entry to the left track and right track accessiblefrom the opposing side of the plate.

The cutting guide comprises a handling feature; left and right guidewalls extending downwardly from the handling feature and terminatingrespectively in left and right horizontal guide blades, the left andright horizontal blades adapted to mate with the left and right tracksof the bone plate respectively; an arm extending downward from one ofthe handling feature, the right guide wall and the left guide wall, andcomprising a flange; a cutting slot disposed on the flange; wherein whenthe left and right horizontal blades are engaged with the left and righttracks of the bone plate respectively; the cutting guide slides in aproximal-distal direction relative to the bone plate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a top isometric view of a bone plate according toone embodiment of the present invention adapted for use in an ulnarshortening osteotomy.

FIG. 1B illustrates a bottom isometric view of a bone plate according tothe embodiment shown in FIG. 1A.

FIG. 1C illustrates a detailed view of the guiding track of the boneplate shown in FIGS. 1A and 1B.

FIG. 1D illustrates a cross-sectional view of the bone plate shown inFIGS. 1A and 1B taken from a location having upward and downward boundtrack.

FIG. 1E illustrates a cross-sectional view of the bone plate shown inFIGS. 1A and 1B taken from a location showing having only downward boundtrack.

FIG. 2A illustrates a top isometric view of a bone cutting guideaccording to one embodiment of the present invention adapted for use inan ulnar shortening osteotomy.

FIG. 2B illustrates a bottom isometric view of a bone cutting guideaccording to the embodiment shown in FIG. 2A.

FIG. 2C illustrates a rear elevational view of the bone cutting guideshown in FIGS. 2A and 2B.

FIG. 3 illustrates the sequence for assembly of the bone plate and bonecutting guide shown in FIGS. 1A-E and 2A-C.

FIG. 4 illustrates the bone plate and bone cutting guide of FIGS. 1A-Eand 2A-C after assembly.

FIG. 5 illustrates the bone plate FIGS. 1A-E implanted on an ulnar boneafter cutting.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1A-E, shown are various views of a bone plate (100)according to one embodiment of the present invention adapted to performan ulnar shortening osteotomy. The bone plate shown is used to guide thesurgeon, together with the cutting guide shown in FIG. 2, to preciselycut the desired length from the ulnar bone, to rejoin the two ends ofthe bone, and to stabilize the rejoined bone ends in compression topromote their subsequent fusion.

The bone plate (100) comprises a substantially elongated metal platehaving tapered distal (101) and proximal (102) ends. The bone plate(100) further comprises a bone contacting side (103) and an oppositeside (104) a left sidewall (110) and a right sidewall (111). The bonecontacting side has a generally cylindrical concave shape whichgenerally conforms, or can be bent to conform, the contour of the boneto be treated. The bone plate also includes a proximal elongated slot(105) and a distal elongated slot (106) which can be threaded orunthreaded. The bone plate (100) further comprises one or more threadedor unthreaded bone screw holes (107 a-d,) suitable for cortical bonescrews or pegs. Some of the bone screw holes (107 a,107 b, 107 c) may beadapted for installation of bone screws substantially normal to the bonecontacting surface, while others (107 d) may be adapted for installationof oblique screws. Oblique screws are particularly useful to applyadditional compression to rejoined bone ends that have been cut at anoblique angle where the screw can be inserted substantially normal tothe angle of the cut. Disposed on the opposing side (104) of bone plate(100) is a recess (109) adapted to receive the tip of a reductionforceps.

Located respectively in the left and right sidewalls (110,111) of boneplate (100) are a left track (112) and a right track (113) extendinglongitudinally along the length of bone plate (100). Tracks (112,113)extend proximally from a track limit point (119). In the shownembodiment, the left and right tracks (112,113) are mirror images andsubstantially identical with symmetrical placement along the left andright walls (110,111) respectively. However, this is not necessary aslong as the tracks are adapted to engage corresponding features (shownin figures described below) in cutting guide (200). As shown in detailin FIG. 1C which applies to either left track (112) or right track (113)of the illustrated embodiment (left track (112) is shown forillustration purposes only), the track comprises an upper bounding wall(114) and a lower bounding wall (115). Lower bounding wall (115) extendsfor the entire length of the track while the upper bounding wall (114)only extends partially from the distal end of the track (119) to alocation (117) before the proximal end of the track (118) creating anoverhead entry (116) to the track.

The relationship between the left (112) and right (113) can be moreclearly seen in FIGS. 1D and 1E. FIG. 1D shows a cross-section of boneplate (100) at a location where the tracks are bound by the upper andlower bounding walls (114, 115). FIG. 1E shows a cross-section of boneplate (100) at a location where the tracks are bound only by the lowerbounding wall (115).

Laser etched, or otherwise affixed to the opposing side (104) of thebone plate (100) is a series of indicia (120), including a zero-markline (121) used to measure the proximal-distal movement of the cuttingguide (200) relative to the bone plate (100)

Referring next to FIGS. 2A-C shown are various views of a bone cuttingguide (200) according to one embodiment of the present invention adaptedto perform an ulnar shortening osteotomy. The shown embodiment of bonecutting guide (200) is adapted to cooperate with the bone plate (100)shown in FIGS. 1A-E. The bone cutting guide (200) comprises a handlingfeature (201) which can optionally be textured and oriented in agenerally horizontal plane having proximal and distal edges (212,213).Extending downwardly from the left and right side of the handlingfeature (201) respectively are guide walls (202,203) which terminate inleft (204) and right (205) horizontal guide blades. The left and rightguide blades (204,205) are situated on the bone cutting guide (200) soas to precisely mate with the left and right tracks (112,113) of thebone plate (100). The interior space (206) bounded by the handlingfeature (201), guide walls (202,203) and the left and right guide blades(204,205) is sufficiently large to permit the bone plate (100), once theguide blades (204,205) are mated to the tracks (112,113), to glide inthe proximal-distal direction without interference from the bone cuttingguide (200). Of course, the distal movement of the cutting guide (200)will be constrained by the track limit point (119).

The cutting guide further comprises an arm (207) which extends distallyfrom one side (left or right) of the handling feature (201), or from theguide walls (202 or 203) as shown in the illustrated embodiment.Extending downward from the distal end of the arm is a flange (208)which incorporates a cutting blade slot (209). The blade slot (209) isadapted to guide a blade from standard oscillating surgical saw or othersimilar bone-cutting device (not shown) to make a set of preciseparallel bone cuts in the target bone. The flange (208) may optionallycomprise a secondary blade slot (210) parallel to, and located proximalof, blade slot (209) to permit for the making of additional cuts at aknown offset (in this case 4 mm) from the first cut without requiringsliding of the cutting guide (200) on the bone plate (100). Similarly,additional blade slots (not shown) may optionally be included on flange(208) to make cuts at different standard offsets from the first cut.

Cutting guide (200) may also optionally include one or more KirschnerWire (K-Wire) holes (211) on one or both of the guide walls (202,203).These K-Wire holes (211) are obliquely oriented and adapted to guideK-Wires into the target bone to temporarily lock the position of thecutting guide (200) relative to the target bone. Alternatively, theposition of the cutting guide (200) may be locked by using a lock screwor clamp (not shown) between the cutting guide (200) and the bone plate(100).

Referring next to FIG. 3, shown are the sequence of steps for assemblyof bone plate (100) and cutting guide (200). In the first step, thecutting guide (200) is placed directly above bone plate (100) with theguide blades (204,205) oriented downward and the opposite side (104) ofbone plate (100) facing upward. Guide blades (204,205) should be alignedwith track overhead entries (116). In step 2, the cutting guide is moveddownward until the tracks (204,205) are resting on lower bounding walls(115). Finally, in step 3, the cutting guide (200) is slid distally inrelation to bone plate (100) until the distal movement is constrained bythe track limit points (119). Although this exemplary illustrationdemonstrates the cutting guide (200) engaging the bone plate (100) fromthe overhead position, the system of the present invention also permitsthe cutting guide (200) to engage the bone plate (100) from the rearposition.

Method of Use

In operation, the following is a listing of the steps typically taken toutilize the disclosed system to perform an osteotomy on the ulnar boneand stabilize the rejoined bone:

1. To expose the ulnar bone, make a 10 cm to 12 cm longitudinal incisionalong the subcutaneous border of the distal to mid ulna.

2. To affix the bone plate to the ulna, use a drill of appropriate size(and optionally drill guides if using locking screws) to place twocortical screws, of appropriate lengths, into two of the distal bonescrew holes (107 a,107 b, 107 c).

3. To affix the proximal elongated slot (105): use a drill ofappropriate size (and optionally drill guides if using locking screws)to place a cortical screw, of appropriate length, into the proximal longslot (105) in the most proximal position.

4. To affix the proximal elongated slot (106): use a drill ofappropriate size (and optionally drill guides if using locking screws)to place a cortical screw, of appropriate length, into the proximal longslot (106) in the most proximal position.

5. Check the placement of the bone plate (100) using fluoroscopy. Ifmisaligned, loosen screws, then readjust plate position and retightenscrews.

6. To attach cutting guide (200) align and install on bone plate (100),using the procedure previously described, the appropriate cutting guide(200) (transverse (not shown) and oblique (FIGS. 1A-E, 2A-C) options areavailable) to the bone plate (100). Position cutting guide (200) suchthat proximal edge (213) is just distal of the zero-mark line (121). Usetwo K-Wires to temporarily fix the cutting guide (200) by driving theminto the K-Wire holes (211) on the cutting guide (200) and into thebone.

7. To make the distal bone cut, using an oscillating saw (not shown),cut the ulna through blade slot (209) on the cutting guide (200). Oncethe ulna has been cut all the way through, remove the K-Wires.

8. Slide the cutting guide (200) proximally until the determinedosteotomy length is achieved. Each laser etched indicia line (120) onthe bone plate (100) corresponds to an additional osteotomy length of 2mm. Use two K-Wires to again temporarily fix the cutting guide (200) bydriving them into the K-Wire holes (211) on the cutting guide (200) andinto the bone.

9. To make the proximal bone cut, using an oscillating saw (not shown),cut the ulna through blade slot (209) on the cutting guide (200). Oncethe ulna has been cut all the way through, remove the K-Wires. Removethe cutting guide (200) from the bone plate (100) and remove the cutbone wafer from the ulna.

10. To reduce the osteotomy, loosen the two screws in the proximal anddistal elongated slots (105,106) and place one blade of an appropriatelysized forceps into recess (109) and the other blade into the head of oneof the loosened screws. In an alternative embodiment, the other blade ofthe forceps can be placed adjacent to the opposite side of the head ofone of the loosened screws. In order to aid in this step, a specializedforceps may be used which has the tip of one blade shaped to mate withrecess (109) and the tip of the other blade shaped to mate with eitherthe driver pattern on the head of the screws or with the side of thehead of the screws. Using the forceps, reduce and compress the ulnarfragments together until adequate compression is achieved across theosteotomy site. Tighten the two screws loosened previously in this step.

11. Use a drill of appropriate size (and optionally drill guides ifusing locking screws) to place one cortical screw, of appropriatelength, into the remaining distal bone screw hole (107 a,107 b, or 107c).

12. If an oblique osteotomy cut was chosen, an oblique lag screw may beplaced across the osteotomy interface. Use a drill of appropriate sizeto place a cortical lag screw, of appropriate length, into the obliquebone screw hole (107 d) of the bone plate (100).

Check the plate and screw trajectories under fluoroscopy for adequateplacement and osteotomy compression and close the incision.

Illustrated in FIG. 5 is bone plate (100) implanted on the ulnar boneafter the osteotomy.

Although described above in connection with certain bone types andparts, namely the ulnar bone, these descriptions are not intended to belimiting as various modifications may be made therein without departingfrom the spirit of the invention and within the scope and range ofequivalent of the described embodiments. Encompassed embodiments of thepresent invention can be used in all applications requiring osteotomyand stabilization of bones.

We claim:
 1. A bone cutting system comprising: a substantially rigidbone plate comprising an elongated body having a proximal end and adistal end and defining a longitudinal body axis; the bone platecomprising a bone contacting side, and opposing side, a left sidewalland a right sidewall, all of which extend between the proximal end ofthe bone plate and the distal end of the bone plate and all of which aresubstantially aligned with the longitudinal body axis; a proximalelongated slot extending through the bone plate between the opposingside and the bone contacting side located adjacent to the proximal endof the bone plate, the proximal elongated slot adapted to receive a bonescrew; a distal elongated slot extending through the bone plate betweenthe opposing side and the bone contacting side and adjacent to theproximal elongated slot but located distally on the bone plate relativeto the proximal elongated slot, the distal elongated slot adapted toreceive a bone screw; one or more bone screw holes extending through thebone plate between the opposing side and the bone contacting side andlocated distally on the bone plate relative to the distal elongatedslot, the one or more screw holes adapted to receive a bone screw; arecess on the opposing side of the bone plate; a left track recessedinto the left sidewall, the left track extending longitudinally betweena track limit point and the proximal end of the bone plate, the lefttrack being bound by an upper bounding wall, and a lower bounding wall,the lower bounding wall extending for the entire length of the lefttrack while the upper bounding wall extends partially from a distal endof the left track to a location distal to the proximal end of the lefttrack; and a right track recessed into the right sidewall, the righttrack extending longitudinally between a track limit point and theproximal end of the bone plate, the right track being bound by an upperbounding wall, and a lower bounding wall, the lower bounding wallextending for the entire length of the right track while the upperbounding wall extends partially from a distal end of the right track toa location distal to the proximal end of the right track; whereinportions of the left track and the right track that are bound only by alower bounding wall provide an overhead entry to the left track andright track accessible from the opposing side of the bone plate; a bonecutting guide adapted to cooperate slidingly with the bone plate, thebone cutting guide comprising a handling feature; left and right guidewalls extending downwardly from the handling feature and terminatingrespectively in left and right horizontal guide blades, the left andright horizontal blades adapted to mate with the left and right tracksof the bone plate respectively; an arm extending downward from one ofthe handling feature, the right guide wall, and the left guide wall, andcomprising a flange; a cutting slot disposed on the flange; wherein whenthe left and right horizontal blades are engaged with the left and righttracks of the bone plate respectively; the cutting guide slides in aproximal-distal direction relative to the bone plate.
 2. The bonecutting system of claim 1 wherein at least one of the proximal elongatedslot and the distal elongated slot is threaded.
 3. The bone cuttingsystem of claim 1 wherein at least one of the proximal elongated slotand the distal elongated slot is unthreaded.
 4. The bone cutting systemof claim 1 wherein at least one of the proximal end of the bone plateand the distal end of the bone plate is tapered.
 5. The bone cuttingsystem of claim 1 wherein at least a portion of the bone contactingsurface is cylindrically concave.
 6. The bone cutting system of claim 1wherein at least one of the one or more bone screw holes is threaded. 7.The bone cutting system of claim 1 wherein at least one of the one ormore bone screw holes is unthreaded.
 8. The bone cutting system of claim1 wherein at least one of the one or more bone screw holes defines ascrew axis that is substantially normal to the bone contacting surface.9. The bone cutting system of claim 1 wherein at least one of the one ormore bone screw holes defines a screw axis that is oblique to the bonecontacting surface.
 10. The bone cutting system of claim 1 wherein therecess is adapted to receive a blade tip of a forceps.
 11. The bonecutting system of claim 1 wherein the bone cutting guide furthercomprises one or more k-wire holes through one or both of the left andright guide walls.
 12. The bone cutting system of claim 1 wherein one orboth of the bone plate and the cutting guide includes indicia adapted tomeasure the length of movement of the cutting guide with respect to thebone plate.